The concept has been under development since 2003, when a two-person suborbital spaceplane was announced under the name Xerus. According to a 2013 report, fabrication and assembly of the Lynx Mark I was underway at that time.[3]

In 2003, XCOR proposed the Xerus (pronunciation: zEr'us) suborbital spaceplane concept. It was to be capable of transporting one pilot and one passenger as well as some science experiments and it would even be capable of carrying an upper stage which would launch near apogee and therefore would potentially be able to carry satellites into low-Earth orbit.[4] As late as 2007, XCOR continued to refer to their future two-person spaceplane concept as Xerus,[5]

The Lynx was initially announced on March 26, 2008, with plans for an operational vehicle within two years.[6] In December of that year a ticket price of $95,000 per seat was announced.[7] The build of the Lynx Mark I flight article did not commence until mid 2013 and, as of October 2014[update] XCOR claims that the first flight would take place in 2015.[3][8] In July 2015 ticket prices increased by 50% to $150,000.[9]

The development program of the XCOR Lynx 5K18 LOX/kerosene engine reached a major milestone in March 2011. Integrated test firings of the engine/nozzle combination demonstrated the ability of the aluminum nozzle to withstand the high temperatures of rocket-engine exhaust.[23]

The flight article Lynx Mark I is claimed as being fabricated and assembled in Mojave beginning in mid 2013.[26] The cockpit of the Lynx (made of carbon fibre and designed by AdamWorks, Colorado) was reported as being one of the items that held up the assembly.[13]

At the start of October 2014, the cockpit was attached the to fuselage.[27] The rear carry-through spar was attached to the fuselage shortly after Thanksgiving 2014.[28] At the beginning of May 2015, the strakes were attached to the airframe.[29] The last major component, the wings, are expected to be delivered in late 2015.[30]

As of February 2011, engine tests were largely complete[19] and the vehicle aerodynamic design had completed two rounds of wind tunnel testing. A third and final round of tests was completed in late 2011 using a "1/60-scale supersonic wind tunnel model of Lynx."[15][19]

As of October 2014, XCOR claimed that flight tests of the Mark I prototype would start in 2015.[3][8][32]

As of March 2011[update], XCOR has submitted the Lynx as a reusable launch vehicle for carrying research payloads in response to NASA's suborbital reusable launch vehicle (sRLV) solicitation, which is a part of NASA's Flight Opportunities Program. XCOR projects 110 km (68 mi) altitude in flights of 30 to 45 minutes duration, while carrying up to 140 kg (310 lb) internal—or 650 kg (1,430 lb) external—of research payload. Flights will provide up to three minutes of microgravity below 0.01 g.[33]

According to XCOR, the Lynx will fly four or more times a day, and will also have the capacity to deliver payloads into space. A Lynx prototype called Mark I was expected to perform its first test flight in 2015,[1][8][34] followed with a flight of the Mark II production model twelve to eighteen months after.[8] XCOR currently plans to have the Lynx's initial flights from the Mojave Air and Spaceport in Mojave, California[35] or any licensed spaceport with a 2,400 meter (7900 ft) runway. Towards the end of 2015[36] or in 2016[1] the Lynx is expected to begin flying suborbital space tourism flights and scientific research missions from a new spaceport on the Caribbean island of Curaçao.[37][38][39]

Because it lacks any propulsion system other than its rocket engines, the Lynx will have to be towed to the end of the runway. Once positioned on the runway, the pilot will ignite the four rocket engines and begin a steep climb. The engines will be shut off at approximately 138,000 feet (42 km) and Mach 2. The spaceplane will then continue to climb, unpowered until it reaches an apogee of approximately 200,000 feet (61 km). The spacecraft will experience a little over four minutes of weightlessness before re-entering the Earth's atmosphere. The occupants of the Lynx may experience up to four times normal gravity during re-entry. Once it has completed re-entry, the Lynx will then glide down and perform an unpowered landing. The total flight time is projected to last about 30 minutes.[22] The Lynx is expected to be able to perform 40 flights before maintenance is required.

^ abcFoust, Jeff (2011-02-28). "Suborbital back out of the shadows". The Space Review. Retrieved 2011-02-28. the 5K18 engine, four of which will power the Lynx ... the last few technical milestones for the engine are largely complete. ... non-toxic reaction control system (RCS) thrusters, a project that Greason said was more challenging in some respects than the larger main engine, but critical to the company’s vision of rapid turnaround times that would not be possible if conventional hydrazine RCS systems are used. The Lynx design has been through two rounds of wind tunnel tests, with a final round planned for later this year for some final tweaks

^Morring, Frank, Jr. (2011-03-23). "ULA, XCOR to Develop Upper-Stage Engine". Aviation Week. Retrieved 2011-03-25. United Launch Alliance (ULA) and XCOR Aerospace are planning a joint effort to develop a low-cost upper-stage engine in the same class as the venerable RL-10, using technology XCOR is developing for its planned Lynx suborbital spaceplane. The two companies have been testing actively cooled aluminum nozzles XCOR is developing for its liquid oxygen/kerosene 5K18 engine for the Lynx, a reusable two-seat piloted vehicle the company plans to use for commercial research and tourist flights.